This invention relates to a method of removing a cylindrical member from a band-forming drum around which the cylindrical member is wound, and for transferring the cylindrical member maintaining its shaped configuration to a building machine at a subsequent process step for forming a green case of a tire. The cylindrical member in this instance includes, as pneumatic tire constituent elements, a cylindrical laminate structure composed of an inner liner, chafers and a carcass ply, and a pair of bead rings which are arranged spaced from each other on the outer circumference of the laminate structure.
In order to form a green case of a tire, it has been a conventional practice to wind an inner liner, chafers and a carcass ply around a radially expansible and contractible band-forming drum to prepare a cylindrical laminate structure. A pair of bead rings of an inner diameter which is larger than the outer diameter of the laminate structure are then arranged outwardly of the laminate structure, as being spaced from each other. Thereafter, the drum is caused to expand radially outwardly to increase its diameter so as to bring the laminate structure into close contact with the inner surfaces of the bead rings, thereby forming a cylindrical member. The cylindrical member is then grasped and transferred by means of a removal and transfer apparatus having grasping members which are adapted to surround the cylindrical member.
In the known removal and transfer method described above, the cylindrical member is simply grasped on its outer side by the grasping members, and the laminate structure is forced onto the inner circumferential surfaces of the bead rings by the expansion of the band-forming drum. Thus, the laminate structure due to the residual internal stresses tends to contract radially inwardly to decrease its diameter. Despite the arrangement of the bead rings, furthermore, regions of the laminate structure which are not engaged by the grasping members are likely to deform. Additionally, the grasping members when grasping the bead rings are in close contact with the laminate structure only, and the bead rings thus tend to move. Owing at least to these reasons, it has been very difficult to exactly maintain the desired positional relationship between the bead rings and the laminate structure. Moreover, the bead rings often exhibit the quite undesirable tendency of partial separation from the laminate structure, depending upon the grasped condition of the bead rings, thereby giving rise to an unsatisfactory formation of green cases and deterioration of its quality.